Method of making bezels for setting precious stones

ABSTRACT

This method of manufacturing bezels for setting precious stones or the like comprises the steps of turning a stock rod in order to form a hollow head followed by a narrow stem therein, milling the lateral wall of the head with a cutter, and severing the stem from the remaining portion of the rod by cutting, so as to obtain a high-precision bezel having a perfect finish. (FIG. 7a).

United States Patent Favre Aug. 14, 1973 METHOD OF MAKING BEZELS FOR [56] References Cited SETTING PRECIOUS STONES UNITED STATES PATENTS [76] Inventor: Henri Victor Favre, 44, rue du 1,157,598 10/1915 Stone 29/10 College, 39-Saint-Claude, France 1,839,909 1/ 1932 Weatherhead, Jr 29/157 1,935,494 11/1933 West 128/218 [22] Filed: Feb. 8, 1972 3,261,072 7/1966 Stanley i 29/l60.6 X

Rela'ed Applicamm Dam Primary Examiner-Charles W. Lanham [63] Continuation-impart of Ser. No. 854,641, Sept. 2, Assistant Examiner-V. A. DiPalma 1969, abandoned, which is a continuation-in-part of Ser. No. 631,978, April 19, 1967, abandoned.

Foreign Application Priority Data Apr. 28, 1966 France 6659538 Oct. 4, 1966 France 6678730 US. Cl. 29/558, 29/10, 29/160.6,

29/417, 29/557, 63/26, 63/27 Int. Cl. B23p 13/04 Field of Search 29/557, 558, 160.6,

Attorney-Robert E. Burns et al.

[5 7 ABSTRACT 4 Claims, 32 Drawing Figures ansmss PATENTED Adi; 1 4191s SHEEIIIIFS METHOD OF MAKING BEZELS FOR SETTING PRECIOUS STONES CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of my copending US. application Ser. No 854,641 filed Sept. 2, 1969 and entitled APPARATUS FOR SWAGING GEM MOUNTS now abandoned, which is in turn a continuation-in-part of my abandoned application Ser. No 631,978 filed Apr. 19, 1967 and entitled PRO- CESS FOR SETTING PRECIOUS STONES DEVICE FOR CARRYING OUT THE PROCESS AND PROD- UCTS RESULTING FROM THIS PROCESS.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of manufacturing bezels for setting precious stones. Various methods have already been proposed for manufacturing bezels constituting supports adapted to receive precious stones or gems secured by setting.

2. Description of Prior Art According to a known method the initial material is a solid rod or bar shaped by die-stamping and subsequently machined to form a central bore in the lateral walls of the resulting tube longitudinal notches are formed to constitute the claws for eventually setting the precious stones or gems.

This method is attended by various inconveniences, notably that of excluding the possibility of obtaining an accurately dimensioned and easily reproducible bezel, thus preventing any mass production as desirable nowadays.

SUMMARY OF THE INVENTION It is the essential object of the invention to provide a method of manufacturing bezels for setting precious stones and gems and consisting of successive mechanical operations affording a high degree of precision in the manufacture of such bezels. I

It 'is another object of this invention to provide a method capable of producing a diamond-cut and therefore perfectly polished, bright and clean bezel.

Another object of this invention consists in providing an improved method permitting of obtaining a bezel provided with an integral gaged perforated stem adapted to combine a high degree of precision with a particularly rapid setting of precious stones by using only simple means.

To this end, thismethod of manufacturing bezels for setting precious stones and the like from cylindrical rod stock is characterized in that a blind bore is firstly formed coaxially into the front face of the rod to constitute a recess of relatively large diameteradapted to receive the precious stone, that the dutersurface of the rod is turned so as to form in the rod portion enclosing said recess a hollow head of which the maximum outer diameter is substantially equal to the rod diameter, and a solid stem adjoining said head but of a diameter smaller than the rod diameter, whereafter longitudinal open notches are cut by milling in the lateral wall of said hollow head which open into said front face of the head and form therebetween claws to be used subsequently for setting the precious stone, said stem of minor diameter being then drilled coaxially and severed by cutting from the remaining portion of the rod.

The method of this invention is carried out by using for the turning and milling operations milling cutters, twist-bits, carbide and diamond tools capable of combinlng a high degree of precision with a very satisfactory finish. Thus, very small and therefore cheap diamonds may be used this solution is applicable only because these small diamonds can be cemented to a tool, since the machining operations are performed under oil spray conditions, thus preventing any overheating of the cement. However, coupled diamonds affording contorted shapes while being extremely simple to cut may also be used. Operating with an ample supply of oil will eliminate completely any loss of gold dust or other precious metal dust.

The turning and milling operations are accomplished on a metal rod constantly clamped in a rotary headstock, so that the rod positioning and centres are extremely accurate and the resulting bezel is also characterized by a high degree of precision, thus facilitating the subsequent setting steps performed by using mechanical means.

DESCRIPTION OF THE DRAWING A complete understanding of the invention may be obtained from the foregoing and following description thereof taken together with the appended drawing, wherein,

FIG. I is a diagrammatic elevational view of the rod stock before the first axial boring operation FIG. 2 is an axial section showing the rod after this first axial boring operation FIGS. 3a, 3b, 3c, 3d, 3e and 3f are diagrammatic fragmentary elevational views showing different ways of performing the rod turning operation FIGS. 4a, 4b and 4c are similar views showing the different steps of a milling operation FIGS. 50, 5b and 5c are diagrammatic elevational views illustrating different successive steps of a modified formof embodiment of the milling operation FIGS. 6a, 6b and 6c are diagrammatic elevational views showing successive steps of a modified procedure for performing the milling operation FIGS. 7a, 7b and 7c are diagrammatic elevational views showing the successive steps of another way of performing the milling operation FIG. 7d is a horizontal section showing on a larger scale the head of a bezel obtained after three milling operations performed in planes shifted by 120 to each other FIG. 7e is a diagrammatic perspective view showing a bezel obtained after the milling operations illustrated in FIGS. 7a to 7d FIGS. 8a, 8b and 8c are diagrammatic elevational views showing the successive steps of another milling operation according to this invention FIG. 8d is a diagrammatic perspective view showing a bezel obtained by performing the milling operation illustrated in FIGS. to 80, and,

FIGS. 9 to 14 inclusive are perspective views showing different forms of embodiment of bezels obtained by the method of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The various steps of manufacturing method of this invention, for the machining of rod stock and cutting of bezels for setting precious stones or the like, will now be described in detail with reference to the different figures of the drawing.

Referring first to FIG. I, there is shown diagrammatically the first step of the method of manufacturing bezels which consists in forming an axial concentric bore in a solid metal rod 1 having a diameter a, by means of a twist-bit 2 having a diameter b inferior to said diameter a. The rod 1 is shown in axial section in FIG. 2 after the boring step, the resulting recess 3 having a diameter b and opening into the front or upper face of rod 1, its depth being denoted p If desired, this recess 3 may comprise adjacent its outer end a shoulder 4 having a diameter intermediate the values a and b, so that the uppermost portion of the wall of recess 3 will be somewhat thinner.

After the boring of recess 1 in rod 1 as shown in FIG. 2, the next step may consist either in milling the claws or turning its outer surface.

FIGS. 3a to 3f illustrate diagrammatically the various turning steps required for obtaining different external contours of the bezel. This turning step is directed to produce at the rod end a head of which the maximum outer diameter is substantially equal to the diameter a of rod 1, this head being connected through a narrower stem 6 to the remaining portion of the rod.

Thus, the head 5 illustrated in FIG. 3a is machined by turning and comprises a cylindrical upper surface 50 having a diameter a, followed by an intermediate tapered or frustoconical portion 5b and then, by another cylindrical portion 50 having a smaller diameter 0 connected to the remaining portion of rod 1 through a stem 6 of reduced diameter the tools implemented for this turning operation are shown diagrammatically at 7.

In the case illustrated in FIG. 3b, the head 8 of generally cylindro-conical configuration has an upper cylindrical lateral surface 8a of relatively great height having a lower frustoconical extension 8b of reduced height, connected to the stem 6 In the example illustrated in FIG. 30 the head 9 comprises two frustoconical sections assembled by their major bases, providing an upper frustoconical surface 9a converging upwards and of relatively great height, connected to the stem 6 through the medium of a smaller frustoconical surface 9b converging downwards and of relatively reduced height.

FIG. 3d also illustrates a head 10 of double frustoconical configuration but of reverse structure, i.e. comprising an upper frustoconical surface 10a converging upwards and of relatively reduced height, having a lower extension in the form of another frustoconical surface 10b of relatively substantial height which is connected to the stem 6.

The head 11 shown in FIG. 3e comprises an upper cylindrical surface 11a of relatively great height connected through a surface 11b having a curved meridian to the stem 6.

Finally, FIG. 3f shows a completely cylindrical head having a diameter a and connected directly to the stem 6 of relatively small diameter.

In all the forms of embodiment illustrated in FIGS. 3a to 3f the tools implemented for performing the turning operation are designated generally by the reference numeral 7.

Of course, the above-described examples of external surfaces of setting heads, obtainable by turning, are shown only by way of illustration, not of limitation, since it will readily occur to those conversant with the art that many other configurations may be given to the external surfaces of the work-piece according to the desired aesthetical effect.

Now, the milling of the bezel claws will be described, it being assumed that the external surface has already been turned, as explained hereinabove.

A first method of milling said claws is illustrated diagrammatically in FIGS. 4a to 40. The milling operation is accomplished by working on a biconical head 10 obtained by turning as illustrated in FIG. 3d. To this end, a milling cutter l3 revolving about a stationary horizontal axis 14 is used. Thus, the rod 1 is fed vertically upwards in order to cause the head 10 to engage the milling cutter 13 which, of course, is positioned in a diametral plane of the head. During this feed movement, the cutter 13 cuts in the hollow head 10 a pair of diametrally opposed notches 15. When the cutter 13 has penetrate to a sufficient depth into the head 10, i.e. to the depth contemplated for each notch 15, the rod 1 is lowered to free same from the cutter l3 and the rod is rotated about its axis through a predetermined angle, whereafter the milling operation is resumed.

FIGS. 5a, 5b and 5c illustrate a similar milling operation performed on the head 5 of FIG. 3a by means of a cylindrical cutter 13. Thus, notches 15 opening upwards and having a rounded bottom are obtained.

In this case, the horizontal axis of rotation 14 of the milling cutter 13a extends across the vertical axis of head 5 and each notch 15 is cut by imparting a vertical reciprocating motion to the head 5 in either direction (but alternatively this motion may be imparted to the cutter 3a), to cut each notch 15 separately, whereafter the head is rotated through a suitable angle.

These longitudinal notches 15 form therebetween teeth 16 adapted to constitute the claws for retaining the precious stones or gems by setting.

FIGS. 6a, 6b and 6c illustrate a milling operation similar to that shown diagrammatically in FIGS. 4a to 4c but performed on a cylindro-conical head 5 by using a cutter 13 cutting only on one-half of the head diameter. The horizontal axis of rotation 14 of this cutter l3 and the vertical axis of the head 5 do not intersect each other in this case and the head 5 is reciprocated along its vertical axis. During each feed stroke of the head, the cutter 13 cuts only one notch 15, so that an odd number of claw 16 can be obtained.

In the specific milling operation illustrated diagrammatically in FIGS. 7a to 7d the rod 1 on which a head 5 has been turned is kept in a vertical stationary position while the axis of rotation 14 of cutter 13 is shifted in a horizontal plane while maintaining this axis parallel to itself. Thus, the cutter 13 travels in a vertical plane x-y while revolving about its axis, this plane x-y intersecting the outer surface of head 5. Thus, during each cutting step or elementary cutting movement the cutter l3 removes from the wall of head 5 the portion extending from the secant plane x-y and the outer lateral surface of the head. As a result, a notch 15 of a width varying as a function of the distance from said secant plane x-y to the axis of rod 1 is obtained, and the smaller said distance, the greater said width. In FIG. 7d it will be seen that by performing three elementary milling steps in three secant planes such as x-y forming an equilateral triangle, three claws 16 cut in the lateral wall of head 5 are obtained at a relative angular spacing of Thus, a three-claw bezel is obtained very easily and rapidly as shown diagrammatically in FIG. 7e.

FIGS. 8a, 8b and 8c illustrate diagrammatically a modified form of embodiment of the milling operation wherein the rod 1 is still kept stationary in a vertical position while a vertical movement of translation is applied to the horizontal axis 14 of rotation of the milling cutter 13.

FIG. 8d illustrates diagrammatically the three-claw bezel obtained through this operation.

Throughout the above-described operations the metal rod 1 in which the bezel is turned and cut is constantly clamped in a rotary head-stock (not shown). Thus, a considerable degree of precision is obtained in the positioning and centering of rod 1, so that the end product, i.e. the bezel, is characterized by a high degree of precision and finish.

When the bezel has been nearly completed through the above-described head-turning and claw-milling operations, it is only necessary to drill the stem 6 concentrically in order to form a bore of very reduced diameter therein, and to cut this stem transversely at its junction with the solid rod 1, and a finished bezel is obtained. Of course, many other forms of embodiment of such bezels may be obtained through the method of this invention, as illustrated notably in FIGS. 9 to 14 of the drawing.

FIG. 9 illustrates a bezel 17 obtained from a head 5 (FIG. 3) of cylindro-conical configuration, which has three triangular claws 16 formed therein.

FIG. illustrates a bezel 18 obtained from a cylindro-conical head 8 and comprising four claws 16 of rectangular configuration.

FIG. 11 shows a bezel 19 obtained from a biconical head 9 and comprising six claws 16.

FIG. 12 shows another bezel 20 obtained from a biconical head 10 and comprising six claws 16.

FIG. 13 shows a bezel 21 obtained fron a cylindrical head 11 having a curved lower portion and comprising six rectangular claws 16, the notches formed between these claws having a rounded bottom.

FIG. 14 illustrates a different bezel 22 obtained from a cylindrical head 12 by milling four secant planes disposed at a relative angular spacing of and forming a square base 23 having disposed at each corner a claw 16 for setting precious stones or the like.

What I claim is I. Method of manufacturing bezels for setting precious stones or gems from a cylindrical stock rod, which comprises the steps of drilling an axial blind bore into the front face of the rod to form a recess adapted to receive the precious stone, turning the outer surface of the rod in order to form in the area of said recess a hollow head having a maximum outer diameter substantially equal to the rod diameter, and a solid stem adjacent to said head and having a diameter smaller than that of said rod, cutting by milling in the lateral wall of said hollow head longitudinal open notches opening into said front face and forming therebetween claws adapted to set the precious stone, axially drilling said stem of small diameter, and cutting said stem from the remaining portion of said rod.

2. Method as set forth in claim 1, wherein said longitudinal notches are cut by producing a relative movement between the milling cutter and the rod in which the hollow head was turned beforehand, said relative movement taking place in a direction perpendicular to the axis of rotation of said milling cutter.

3. Method as set forth in claim 1, wherein said longitudinal notches are cut by producing a relative movement between said milling cutter and the rod carrying the hollow head in a direction perpendicular to the axis of said rod.

4. Method as set forth in claim 1, wherein said longitudinal notches are cut by producing a relative longitudinal movement between said milling cutter and the rod carrying the hollow head in a direction parallel to the rod axis. 

1. Method of manufacturing bezels for setting precious stones or gems from a cylindrical stock rod, which comprises the steps of drilling an axial blind bore into the front face of the rod to form a recess adapted to receive the precious stone, turning the outer surface of the rod in order to form in the area of said recess a hollow head having a maximum outer diameter substantially equal to the rod diameter, and a solid stem adjacent to said head and having a diameter smaller than that of said rod, cutting by milling in the lateral wall of said hollow head longitudinal open notches opening into said front face and forming therebetween claws adapted to set the precious stone, axially drilling said stem of small diameter, and cutting said stem from the remaining portion of said rod.
 2. Method as set forth in claim 1, wherein said longitudinal notches are cut by producing a relative movement between the milling cutter and the rod in which the hollow head was turned beforehand, said relative movement taking place in a direction perpendicular to the axis of rotation of said milling cutter.
 3. Method as set forth in claim 1, wherein said longitudinal notches are cut by producing a relative movement between said milling cutter and the rod carrying the hollow head in a direction perpendicular to the axis of said rod.
 4. Method as set forth in claim 1, wherein said longitudinal notches are cut by producing a relative longitudinal movement between said milling cutter and the rod carrying the hollow head in a direction parallel to the rod axis. 